The following is an ongoing, fairly conservative roster estimate based on players under contract for the 2012-13 season. Spots currently set to be up for grabs or unfilled have been left blank for the time being. Cap hits are shown, not salary.

The Caps currently have 49 players under NHL contract for the '12-13 season (not counting Wilson).

The 2012-2013 off-season salary cap is set to ~$77.22M however, as with the current cap figure for next season, much uncertainty remains given the current CBA's expiration on 9/15/12.
There's a fair likelihood the eventual cap number will be smaller.